News Release

Contact: Sondra Katzen, Public Relations, 708.688.8351, sondra.katzen@czs.org

June 9, 2020

FOR IMMEDIATE RELEASE

Chicago Zoological Society and University of Illinois Scientists make Discovery that could aid in Future Conservation for the Endangered Humboldt Penguin

Findings Published in PLOS ONE

Brookfield, Ill. — From March to December every year, Humboldt penguins nest in vast colonies on the Peruvian and Chilean coasts of South America. The lucky ones find prime habitat for their nests in deep deposits of chalky guano (excrement of sea birds used as a fertilizer) where they can dig out sheltered burrows. The rest must look for rocky outcrops or other protected spaces, which are more exposed to predators and environmental extremes.

In a new study, recently published in PLOS ONE, researchers from the Chicago Zoological Society and the University of Illinois looked at metabolic markers in the blood of 30 Humboldt penguins nesting in the Punta San Juan Marine Protected Area in Peru. The scientists wanted to know if there were metabolic differences between penguins nesting in the guano-rich burrows and in the exposed areas.

Nesting success is critical to the Humboldt penguin’s long-term survival as a species. Decades of aggressive guano harvesting in the late 19th and early 20th centuries—a practice eventually replaced with more sustainable methods—depleted the Peruvian coastline and near-shore islands of their historical guano deposits that provided habitat for nesting penguins. Guano mining, climate change, and other threats have led to a dramatic decline in Humboldt penguin populations across their range. Today, there are only about 32,000 of the birds—down from hundreds of thousands less than a century ago—and their numbers continue to fall.

“Punta San Juan and other protected marine areas and reserves along the coast of Peru still provide some protected sites with good guano deposits that the penguins are able to dig into to make their nests,” said Dr. Michael Adkesson, vice president of clinical medicine for the Chicago Zoological Society, which operates Brookfield Zoo. Adkesson led the research with David Schaeffer, a professor emeritus of veterinary clinical medicine at the University of Illinois at Urbana-Champaign; and Jeff Levengood, a researcher with the Illinois Natural History Survey, which is a division of the Prairie Research Institute at the University of Illinois.

“We know from studies by Peruvian biologists that penguins produce more chicks with higher survival rates when they are able to dig burrow nests into guano deposits,” Adkesson said. “So we wanted to see if we could detect—based on the blood of these birds—metabolic differences that would indicate the penguins nesting in less ideal nest sites were using more energy to deal with the fact that they are more exposed to the elements and predators.”

The task was a challenge because few studies have analyzed blood metabolites in birds and the researchers did not have a hypothesis about what they would find, said Schaeffer, who, with Levengood, conducted the statistical analyses of 19 saccharide metabolites.

Their work revealed that penguins in sheltered and unsheltered locations had consistent—and distinct—patterns of several sugars in their blood. The blood sugars that best predicted the birds’ nesting habitat included arabinose, maltose, glucose-6-phosphate and levoglucosenone.

That last sugar is a metabolic byproduct of exposure to a pollutant, levoglucosan, which is generated by the burning of cellulose. Setting fire to agricultural waste is common in regions near the nesting colony. Forest fires also generate levoglucosan. This metabolite was higher in the birds in exposed nests.

“This unexpected finding is one of the few indicators that we have of the unsheltered penguins being exposed to more air pollution than their counterparts in burrows,” Schaeffer said.

The differences in the other saccharides likely reflect the extra metabolic stresses the penguins in exposed nest sites experience, the researchers said. More research is needed to tease out the relationships between these metabolites and their health.

“This is another tool in the toolbox of understanding what’s going on with the penguins in this region,” Adkesson said. “We know the penguins can adapt to the lack of good nesting habitat to some extent, but it’s not ideal for the long-term survival of the species. We hope that by looking at what’s going on in their blood we can better predict how changes in the environment will affect their health and reproductive success, with the ultimate goal of shaping conservation strategies that protect the penguins and their habitat.”

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Editor’s Notes:

The paper “Effects of nest type and sex on blood saccharide profiles in Humboldt penguins (Spheniscus homboldtii): Implications for habitat conservation” is available at https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0233101.

To reach Diana Yates, life sciences editor, University of Illinois, 217.333.5802; diya@illinois.edu
 

About the Chicago Zoological Society

The mission of the Chicago Zoological Society is to inspire conservation leadership by engaging people and communities with wildlife and nature. The Chicago Zoological Society is a private nonprofit organization that operates Brookfield Zoo on land owned by the Forest Preserves of Cook County. The Society is known throughout the world for its international role in animal population management and wildlife conservation. Its Center for the Science of Animal Care and Welfare is at the forefront of animal care that strives to discover and implement innovative approaches to zoo animal management. Brookfield Zoo is the first zoo in the world to be awarded the Humane Certified™ certification mark for the care and welfare of its animals, meeting American Humane Association’s rigorous certification standards. The zoo is located at 8400 31st Street in Brookfield, Illinois, between the Stevenson (I-55) and Eisenhower (I-290) expressways and also is accessible via the Tri-State Tollway (I-294), Metra commuter line, and CTA and PACE bus service. For further information, visit CZS.org.
 

Photo Captions—credit: Mike Adkesson

2708: Thousands of Humboldt penguins nest along a protected shoreline in Peru, South America.

2944: A new study of Humboldt penguins reveals metabolic differences between those that nest in sheltered and exposed areas.

4820: Some penguins must make their nests in more exposed areas.

5848: Traditionally, Humboldt penguins nest in burrows dug from the chalky deposits of centuries of bird guano. The burrows protect them and their young from predators and the weather.

5592: A research team, including Dr. Michael Adkesson, vice president of clinical medicine for the Chicago Zoological Society (pictured right) extracts blood from a nesting Humboldt penguin for analysis of the bird’s metabolic status.

MEDIA CONTACT:

Sondra Katzen
Media Relations Manager
Office: 708-688-8351
Cell Phone: 708-903-2071
E-mail: Sondra.Katzen@CZS.org

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